var zr = zrender.init(document.getElementById('main'));

var circle = new zrender.Circle({
    shape: {
        cx: 150,
        cy: 50,
        r: 40
    },
    style: {
        fill: 'none',
        stroke: '#F00'
    }
});
zr.add(circle);

var R_DEFAULT = 40;

document.getElementById('btn01').onclick = function(){
	var r = circle.shape.r;
	if( r > 100 ){
		circle.attr('shape', {
			r: R_DEFAULT
		});
	}else{
		circle.attr('shape', {
			r: (r+10)
		});
	}
};





